On Wed, 2015-04-22 at 12:06 +0200, Christophe Leroy wrote: > diff --git a/arch/powerpc/include/asm/mmu-8xx.h > b/arch/powerpc/include/asm/mmu-8xx.h > index d41200c..1407034 100644 > --- a/arch/powerpc/include/asm/mmu-8xx.h > +++ b/arch/powerpc/include/asm/mmu-8xx.h > @@ -27,6 +27,19 @@ > #define MI_Ks 0x80000000 /* Should not be set */ > #define MI_Kp 0x40000000 /* Should always be set */ > > +/* > + * All pages PP exec bits are set to 000, which means Execute for Supervisor > + * and no Execute for User. > + * Then we use the APG to say whether accesses are according to Page rules, > + * "all Supervisor" rules (Exec for all) and "all User" rules (Exec for > noone) > + * Therefore, we define 4 APG groups. msb is _PAGE_EXEC, lsb is _PAGE_USER > + * 0 (00) => Not User, no exec => 11 (all accesses performed as user) > + * 1 (01) => User but no exec => 11 (all accesses performed as user) > + * 2 (10) => Not User, exec => 01 (rights according to page definition) > + * 3 (11) => User, exec => 00 (all accesses performed as supervisor) > + */ > +#define MI_APG_INIT 0xf4ffffff > + > /* The effective page number register. When read, contains the information > * about the last instruction TLB miss. When MI_RPN is written, bits in > * this register are used to create the TLB entry. > @@ -87,6 +100,19 @@ > #define MD_Ks 0x80000000 /* Should not be set */ > #define MD_Kp 0x40000000 /* Should always be set */ > > +/* > + * All pages PP exec bits are set to either 000 or 011, which means > respectively > + * RW for Supervisor and no access for User, or RO for Supervisor and no > access > + * for user. > + * Then we use the APG to say whether accesses are according to Page rules or > + * "all Supervisor" rules (Access to all) > + * Therefore, we define 2 APG groups. lsb is _PAGE_USER > + * 0 => No user => 01 (all accesses performed according to page definition) > + * 1 => User => 00 (all accesses performed as supervisor > + * according to page definition) > + */ > +#define MD_APG_INIT 0x4fffffff
"exec" bits or data? -Scott _______________________________________________ Linuxppc-dev mailing list Linuxppc-dev@lists.ozlabs.org https://lists.ozlabs.org/listinfo/linuxppc-dev
